1. Field of Invention
The present invention relates to a signal shifting device, and more particularly to an optical channel shifting device.
2. Description of Related Art
Refer to FIG. 1 and FIG. 2. An optical fiber channel adjuster 1 includes a first optical fiber aligner 11, a second optical fiber aligner 12, a first output optical fiber 13, a second output optical fiber 14, a relay 15 and an input unit 16. The first optical fiber aligner 11 has a first V-type indentation 111 and the second optical fiber aligner 12 has a second V-type indentation 121 parallel to the first V-type indentation 111. The first output optical fiber 13 is mounted in the first V-type indentation 111 and the second output optical fiber 14 is mounted in the second V-type indentation 121.
The relay unit 15 includes a container 150, two electromagnets 151, a supporting shaft 152, a performing lever 153 and a rectangular block 154. The electromagnets 151 are fixed in the container 150 bilaterally. The supporting shaft 152 is secured between the electromagnets 151. The performing lever 153 is jointed on the supporting shaft 152. The rectangular block 154 is mounted on a surface of the performing lever 153.
The input unit 16 includes a supporting cylinder 161 and an input optical fiber 162. The input optical fiber 162 is supported by the supporting cylinder 161 and retained against the rectangular block 154.
The electromagnets 151 moves a free end 155 of the performing lever 153 between an upper and a lower position. When the free end 155 of the performing lever 153 is moved and kept in the lower position, the rectangular block 154 mounted on the surface of the performing lever 153 pushes a terminal 163 of the input optical fiber 162 into alignment with a terminal 131 of the first output optical fiber 13. When the free end 155 of the performing lever 153 is moved and kept in the upper position, the rectangular block 154 mounted on the surface of the performing lever 153 pushes a terminal 163 of the input optical fiber 162 into alignment with a terminal 141 of the second output optical fiber 14.
As the description above in accordance with the conventional optical fiber channel adjuster 1, the input optical fiber 162 touches the rectangular block 154 in the form of line-contact. In addition, the rectangular block 154 is typically made of stainless steel or ceramics.
On the basis of the durability test for the optical channel shifting, the test standard of the Telcordia GR-0173-CORE 107 cycles must be conformed to. Because of the larger contact area and the friction between the stainless (or ceramic) and the optical fiber, the damage to optical fiber surface results in optical leakage and the increased insertion loss (ΔIL>0.2 dB) after the 0.5×107 time durability test. As a result, the test standard of the Telcordia GR-0173-CORE 107 cycles cannot be met.
Thus, there is a need to develop an optical channel shifter to reduce the friction caused by the input optical fiber during the shifting period to lessen the insertion loss and meet the durability test standard.